The first computers, which used vacuum tubes, were often enormous in size, occupying entire rooms. They were very expensive to operate. In addition, they used a great deal of electricity, generated a lot of heat which was often the cause of malfunctions. The first computers were developed for the atomic energy industry.
Those computers relied on machine language to perform operations and they could only solve one problem at a time. Machine languages are the only languages understood by computers and they are almost impossible for humans to use because they consist entirely of numbers. Therefore, high level computer programming language is used. Every CPU has its own distinctive machine language. Programs must be rewritten to run on different types of computers. Input was based on punch cards and paper tapes while output was displayed on printouts.
During second generation, the transistor was invented in 1947 but didn't see wide spread use in computers until the late 50s. But later on, transistors became the key component in all digital circuits including computers. Today's latest microprocessor contains tens of millions of microscopic transistors! The microprocessors brought the latest generation of computers. Thousands of integrated circuits are built up into a single silicon chip that contains a CPU. The silicon chip has reduced the size of computers from the bulky slow computers to a size of computers that can be fixed on desktop or laptop.
Modern computers are far superior allowing them to become smaller, compact, faster, cheaper, more energy saver, more reliable than their first generation predecessors. The computers are getting smaller; hence speed, power and memory have relatively increased. New discoveries are constantly being modified in computers that affect the way we live, work and play. With the latest innovation in technology, computers have become an ultimate necessity for all. Therefore, need of refurbished, cheap computers or used computers have also arisen! Manufacturers of refurbished computers are providing satisfactory service by creating cheap computers with affordable price, giving same performance as the brand new machine. As majority of people are unable to buy new branded models, they opt to buy used computers, cheap refurbished computers which are easily available, convenient to use and works efficiently. Moreover, it is a great means to save money.
The next generation of computers will probably be based on artificial intelligence, which is under development process. It is a branch of computer science concerned with making computers behave like humans! Scientists are beginning to use the term Nanotechnology, although a great deal of progress is yet to be made. Huge research work is required for the development of software to enhance computer works and its robotic applications!